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Jann. 27, 1931. H. H. HARD'ISNGE LAWN IOWER GRINDER Filed m515, 192sl 5 Sheets-Shea*l 1 NW mm, ./.QNI Gm, mw. u e z- NW bibi w .I n u uw uw w vw "wn mv ,131 \m wh A $1 mw hm ww @Nl -NN Q. MN fl.\\ N Nx 1|\\ l um. QN MN llwlmlHHHHllllllllllllhUll UHIH 1| HHHHHHIHWWHHHI 1MM.. I I- :m -.\J NGN J L.. QN wm m. L r www hm, a -Mwmm.--::--i:i-l :mm: e@ m--. --i Xml- L.

Jan. 27, 1931. H. H. HARDINGE v 1,790,471

' LAWN uowER GRINDER Filed Aug. l5, 1928 5 Sheets-Sheet 2 Jan 27, 1931. H. H. HARDINGE LAWN uowER GRINDER' Filed Aug. 15, 1928 5 Sh'veets'-Sheet 5 ,rr/15115511111..1r/$1155;

Jan. 27, 19.31. H. HARDINGE y 1,790,471

` LAw lowER GRINDER Filed Aug. 1,5, 192B 5 Sheets-Sheet 4 Jan. 27, 1931.

H. H. muanllmsl` LAWN IOWER GRIND'ER Filed Aug. 15. 1928 5 Sheets-Sheet 5 y15 To the attainment of these ends andthe lieferring moreparticularly to the draw 6 Patented Jan. A27', 1931 I i w i Unire saires A'rsN'rfoi-Fica e nanny n. sername-n, on carence., rLLrNors, Assrenon ro. sARAnJNEnAnDrNen, y

, or cnrcaso, ILLrNors Y LAWN-ironas Glimmen Application led August 15,` 1928. Serial No. 299,678.

rl`his invention relates to improvements in Figure ll is a detail view partly irrelevalawn mowergrinder, and one of the Objects tion and partly in section 1of the companion of the same is to provide a machine of this member to the member shown in Figure 8. character which will be of a simple and com- Y Figure l2 is an enlarged detail viewpartly 5 'pact arrangement; which ,may be successfulin -eleva-tioiiand partly in verticali-section il- 55 ly operated without the services of an expert, lustrating the manner of using this sharpenand by means of which machine the spiral' as Aing device Afor what known' as putting well as the stationary blad-'e or knife may be green mowers. i I ground or sharpened, and with the further y Figure 13 is a detailperspective view of a result that the spiral blades will have a close ground plate or bladc of the mower. 6U fitv and a proper clearance with respect to Y Figure lil is an'elevation taken from the fthe stationary blade or knife, thereelblades front of the grindingwheel and' showing the being ground or sharpened without detaching work supporting wheel in" connection theretherefrom the mower. with.

accomplishment of other new and useful obings the numerals l5 designate uprights of jects as will appear, the invention consists in any desired size and configuration which are the `features ofnovelty in substantially the mounted upon rollers oricasters i6 that rest aconstruotion, combination and arrangement upon the ground or floor. and carried by these of the several parts hereinafter more fully uprights is a support 17 and upon this sup- 70 described and claimed andshown in the ,acport is arranged parallel tracks or guides companying drawings illustrating this inl8--l9- The support l? with the guides itl ventionfand in which and 19 may be of any desired length and Figure ljis a front elevation of amachine mounted to travel thereupon carriage 20, of this character constructed in accordance having peripherally grooved rollers 2l which 75 with the principles of this invention. I Aei'igage and roll uponthe track or guide ib Fic'ure 2 isa to D lan view of Fwure l. and fiat rollersQQ which engas've and roll uiiozi e P. t .1 "Y e I Figure 3 is a vdetail horizontal sectional the guide or traf-k i9. liy means ot trie proview taken on line 3-'.3,`Figure'll. vision oi the grooved rollers 2l itV will lie SO .Figurelis aview takenfromthe left hand manifest that the carriage will be held iii so end of Figure 2 withparts in section and with proper position with relation to the tracks or parts broken away for theV sake of clearness. guides and will be preif'entedfrom being lat- Figure 5 is a view as taken on lmet-5, erally displaced, stops 28 being arranged at Figure 3, partly in elevation, partly in Vertisuitable point-s upon the track or guide 1S for cal section and partly broken away.V limiting the traveling movement of the Y :ar- 85 Tigure 6 is a detail perspective view of the ,ri-age. i 1 l A upper portion of the, machine showing the lSecured to this carriage and extending la wn mower in position with respect thereto. transversely thereaeross Vare uprights Trfigure 7 is a detail view in side elevation which are preferably `formed of material of 4G of one of the supporting members forthe comparatively small gauge and are spaced 90 mwen i from each other for any suitable distance.

Figure 8 is a view similar to Figure 9 of Reniovably mount-ed upon the i'nenibere. the supporting member which cor-operates is. a support Qprovided with a notch or seat with the supporting member shown in liligure 2'( preferably of a V shaped configuration.

7 and havingattaehed thereto aisupport-for lhis support 26 is provided with spaced de- 95 the stationary blade. i Y pending portions which are adapted to stand AFigure 9 is a detail'sec'tional view taken on asti-.ide of the upper edge of the upright 2l line 9i 9,Figure 7. K so as to move longitudinally thereupon.

Figure l() is a. detail sectional view taken' on Thumb screws V28 are provided i and are l i Y threaded through spaced port-ions 29v carried 100 line l0-l0, Figure 8.

by the support 26 so as to engage the ends of the rod 30, which latter is provided with a plurality of recesses 3l. rl`he rod 30 is supported by and moves through a bearing '32 that is secured to the upright 24 as at lVith this` construction it will be manifest that when the screws 28 are respectively adjusted, and when the rod 30 is maintained stationary, the support 26 will be bodily moved with respect to the upright 24.

Projecting through the bearing 32- is a screw or fastening element 3-l which is adapted to engage in the recesses 3l. By retracting the screw or fastening element 3% and adjusting` the support 26 upon the upright the rod 30, being held in position by means of the screws 28. will freely move through the bearing 32 until one of the recesses 3l is positioned adjacent the end of the screw or fastening element 34. This will permit of a general adjustment of the support lVhen the latter is in position and the fastening element Sli seated in one of the recesses 3l, a further adjustment of the support 26 with respect to the upright 24: may be obtained by a proper adjustment of the screws Q8.

The upright 25 is provided with a series of recesses 35 opening through the upper edge thereof and mounted so as to slide upon the upright 25 is a support 36 having a recess 37 opening through the upper edge thereof, which co-operates with the bearing 27 in the support 2G. Carried by the support 36 is a projection or pin 38 that is adapted to enter the grooves or notches 35 in the upright so that the support 36 may be adjusted lengthwise of the upright 25 by disengaging the pin or projection 38 from the notches or recesses 3.3 and when the supportI 36 is positioned the pin or projection 38 will enter one of 'the notches or recesses 35 to hold the support 36 against. adjustment with respect to the upright 25.

Depending from the support '17 is a tuhuiar member 39, the lower end of which receives a pin or projection 40 mounted upon a base plate or member il that rests upon the ground or lioor, so that the uprights 15 and the structure superposed thereupon will be adapted for movement upon the ground or floor at the will of the operator, and for the purpose of positioningthe mower with respect to the sharpening element, to be described, at the will` of the operator.

In order to maintain these parts in their adjusted position there may be provided a bar or rod 42 which isl connected as at 43 witl. one of the uprights 15 at one end, the other end vof the bar passing loosely tin-ough a bearing' Lli` which is swiveled as at 45 in a suitable bearing carried by the member 41. A fastening screw e6 is adapted to engage the rod 42 where it passes through the bearing 44: t'or locking the parts in their adjusted position. Thusby loosening the screw -i6 the carriage and the structure which supports the carriage may be moved into any desired position with respect to the base plate 4l. After the desired adjustment has been obtained the screw i6 may be tightened for maintainingl the carriage in the position desired A sharpening element 47, preferably in the form of a hollow frustro-conical member is secured to a shaft 46 and is journaled in a sleeve or bearing 49 that is carried by a frame 50. The frame preferably embodies uprights that are connected together at their lower extremities by means of members 5l and the frame is pivotally supported by means of pivots passing through the meinbers 5l and engaging a plate or member :B5- which rests upon the base plate el, so that thi` frame may rock about the pivot 52 when desired. 'l'he member 53 is provided with a dependingr flange 5e that enters a socket or recess in the base plate all so as to form a fulcrum or pivot for the member 53 and the frame 50 to be rocked upon.

It is sometimes necessary to raise and lower the sharpening element 4.7 and in order to accomplish this movement the member 53 is rocked with respect to the base plate 4l, and in order to maintain the frame 50` and the sharpeningl element i7 in a proper upright position when the member 523 rocked, the pivots 52 betweenlthe frames 50 and the meniber 53 is provided. rlfhe member 53 is rocked about the fulcruin .5d-55 inany suitable manner, but preferably by means of levers 56. pivotaily supported intermediate their ends as at 57. Connected with one end of the levers are rollersI 58 which are adapted to engage the lioor and pivotally connected to the other end the levers as at 5S) is a bearing 6(7), in which one end of a shaft 6,1 is journaled. Connected tothe shaft 6l is a crank handle 62 and the other end of the shaft 61 is threaded as at 63 to engage i bearing 6l which is pivotally connected to the frame 5d. Thus, when the crank 62 is operated the shaft 6l will be. threaded into or out of the bearing 64;, according to the direction of rotation of the shaft to cause the rollers 5S on the. ends of the levers 56 to move into or out of engagement with the floor or ground or the base plate 41, with the result that the member 5?) will be rocked about the fulcrum :Sill- 55 to raise or lower the frame and with it the grinding or sharpening. element 47.

Any suitable means may be provided for.

rocking the. element 5() about its pivot 52, but a simple and eiiicient means embodies an upright 65 which may be supported in any suitable manner, preferaliily by means of brackets connected with the depending tubular member 39. This upright 65 extends to a point in proximity to the sharpening element 47 and has loosely n'iounted thereupon a collar 67.

llt)

Pivot-ally connected with the collarY as at 68 is a rod 69 havingl a. threaded portion 70 and a reduced portion'l. The rod passes through the frame 50 and the reduced portion 71 passes througha cross bar 72 on the frame. Threaded upon the endof the reduced portion 71 is a nut 78faiid interposed between the nut 78 and the cross bar 7 2 and encompassing the reduced portion 71, vis a spring Y74 which tends normally to move the Vtrame V50 to the right in Figure 4 so as to hold the grinding element 47 against the blade being` sharpened.

Threaded upon the portion oi the rod (39 is a hand wheel'75 which is provided with a sleeve 70 extending` over a portionV ofthe rod to protect the same. *A sleeve or collar 77 is interposed. between the element 75 and the cross bar 72 and against which trie hand wheel operates. V p

It will be manifest by operating the hand wheel 7 5 the tension ot the spring 74 may be varied and as the rod 69 is pivotally Acon- -iiected as at 68 with the collar 67, and inasmuch as the upright 65 remainsstationary, when the trame -50 is rocked about ,its pivot 52, the pivot 68 will permit of this movement of the frame andV will not interfere "with the adjustment of the frame.

Mounted also upon the Jframe 50 is a motor 78 of any desired type, preferably of the electric type, and connectedvto theshaft ot the motor is a pulley 79 over which a drive belt 80 passes, and the drive belt also passes over a pulley 81 onthe shaft 48 to which the grinding element 47 is connected so that the grinding element and the power mechanism Vfor actuating the same in connection with the Jframe 50, constitutes a single unit. n

The grinding element 47 is adapted to be' moved to Yard and away from the work and with respect to the traine 50 in any suitable manner. such as by means ot a. lever 82'which pivotally mounted as at 88 upon the traine 50. Mounted upon the sl' t5 is a sleeve 84. and arms 85 connected with a collar 86 are adapted to move the shaft 48 and the grinding element 47 toward and away from the work. This is accomplished by means of pins or projections 87 which pass through suitable slots in the sleeve 84'and engage in a grooved collar on the shatt 48 so that the shaft may be longitudinally reciprocated while the rotation thereof will not be interfered with.

A spring 88 is interposed between a portion of the frame 50 andthe collar 86 Vand tends normally to move the collar 80 in one direction. Connectedwith the lever 82 arefpins 89 which enter a peripheral groove in the collar 86 so that when thelever is rocked about its pivot` the collar U0 will be ,moved but the rotation thereof will not be'intertered l lwith. n Y

/Vheii it -is desired to sharpen the spiralv blades of the mower, the stationary blade is the mower vwillV then rest against a stop device 92 which maybe of any desired coniiguration, but preferably embodies a head 92 A, on a threaded shaft 98, which latter vpasses through a bearing 94 carried by a-'supj'iorting member 95.

The Vsu'ipoi'ting member 95 is connected to the carriage by means of uprights preterably ot' tubular construction, and which upriglits rest upon a plate or ledge 97 on the carriage. '.l his plate 97 is provided with V,a plu rali/ty ot apertures 98 therethrough and a rod or bar 99 passes through the member 95, tubular members 9o, and plate or member 97 through one ot the apertures 98 tliereot,`and

the rod is held in position by means ot a nut or collar 100 threaded on to the extremity thereof. By adj Listing the threaded member 93 in its bearing94 the position of the stop or rest 92 may be varied so as to determine the angle i at which the mower may be placed and held withinthe machine. At the same time the upriglits 96 may be bodily adjusted by means oitl the apertures 98 in the member 97.

. After the mower has beenthus positioned -andrin the event it is desired'to secure a micrometer adjustment, the thumb Vscrews 28 (see particularly Figure 7) are adjusted for that purpose. p Y

YVhen the mower isin the position shown in Figure 4, the edge ot the grinding element 47 will engage the edge of the spiral blades 101 o't the mower and the spring 74 ieu will hold thergrinding element yieldiuglyg in engagement with the spiral blades.

A suitable support may be provided ior holding the spiral blades in position during the operation ot'V the grinding element, such as: aV roller 102-mounted tor freerrotation upon a shaft 103, which in turiris mounted upon VaV support 104 connected to and depending trom the sleeve 84, preferably by the sleeve passing through the support 104 and a thumb screw 105 is provided for holding the roller102 inlposition. In this position and as shown in Figure 4, the spiral blade will be supported and be properly held during :the grinding operation.

When desired and in order toget the snpport-ing roller 102 out of the way, the thumb nut 105 may be loosened and the support 104 swung-'about the sleeve 84to position the roller 102 above the grinding element 47.

Thus it will be seen that there will be provided ,a compact `and simple Vconstruction wherebythe propersharpening otl thespiral blades will be insured. As the grinding eleiin ment 47 progresses trom one, end of the plate to the other, the spiral blades may be bodily rota-ted.

With this improved machine it will also be possible to sharpen the blades from both ends thereof, that is to say after the work larriage has traveled the length ot the blade in one direction, it may be caused to be moved haclrwardly in the opposite direction. On either bodily movement ot' the work carriage and itl desired in order to prevent the spiral blades from rotating` a slight pressure may be exerted upon the blades by the hand of the operator.

In Figures 8 and 11 there is shown a modiiicd form ot support for holding` the stationary blade in position to be ground. In order to grind the stationary blade it is rcmoved trom the mower and a support 106 provided which is similar to the support itl and is interchanged with the support 36, a pin 10T on the support 106 enteringv the grooves or recesses 35 in the upright Connected with the support 106 is an upright- 108 having slots 10Q-110 arranged at angles to eachother so as to support the stationary blade 111 in either the full line or dotted line position shown in Figure 8, to be engaged by the grinding element 47.

In order to prevent the support 106 troni becoming detached from the upright thumb nuts 112 may be provided.

The companion support 113 which cooperates with the support 106 is similar to the support :26. with the exception that in lieu of the bearing 27 an upright 114, similar to the upright 10S is provided, and this upright 114 is provided with grooves 115 similar to the grooves 10Q-110, for holding the stationary blade in one of two positions.

The. support 113 is adapted to engage over the edge otl the upright Q4 and held against displacement by means of thumb nuts 110. i t'ter the supports 11B- 106 have been adjusted and the stationary blade 111 secured thereto, a micrometer adjustment may be. secured by adjusting' the support 113 in the same manner that the support 26 is adjusted by means of the bar or rod and the thumb screws lilith this improved construction it will be manifest that the carriage 20 carrying the worlr is reci procatcd upon the tracks or guides 1.8-19 and with respect tothe grinding' element 4T. the carriage willV be guided in a straight line due to the tact that the grooved roller Q1 receivingv the edge ot the track or guide 18 will hold the same against lateral displacement,

The spiral blades will be heldin position by means of the supporting roller 102 and the grinding element will engage the blades at. the proper angle.

The grinding element 4T will be. yieldingly held against the edge ot the plate by means of the springe 74, the tension oi which may be varied.

The carriage and the supportingl structure therefor is adapted tor a tree pivotal movement with respect to the base 41 about the pivot 40, and the frame with the supporting` structure is adapted to be raised and lowered with respect to the base plate 41.. This will cause the supporting plate or meniber 53 to rock a aout the tulcrum 54 and during; this rocking movement andas the trame 50 is bodily raised it. may be swungl about its pivot so as to properly position the grinding' element 4T with respect to the work.

Vlith this construction it will also be manitest that thc edge of the sharpeningl element 47 will always be parallel with the edge ot the blade of both the rcel and the stationarj.' blade.

llurthermo-re, the frame 50 which carries the motor and the sharpening,` element is adapted for both a vertical and a pivotal adjustment to enable the operator to provide a proper clearance on the reel blade and a proper position with relation to the lower edge of the grinding wheel.

In Fi'eure 12 ot' the drawings the device is illustrated as being used in connection with the type of mower known as putting` green mowers7 in which the mower is held in a position that the upper edge of the knives 11T will be-engaged and sharpened by the upper edge of the grinding wheel' 4T or the portion of the grinding wheel which is above the axis ot rotation ot the grinding wheel so that the grinding wheel can grind ample clearance upon the reel without touching the spiders 118 which support the blades 117 in position and without interfering' with the next blade. This is particularly advantageous as in putting green mowers the blades 11T are arranged very close together. In this` torni o'l` the invention a disc 11S) is rotatablyY supported as at 120 by an arm or bracket lil which is secured to the shaft 10S that is carried by the support 104.

The disc is ot a diameter consiilex-ably1 greater 'than the diameter ol" the adjacent face of the grinding' wheel 47 so as to summit the work up to the end ot the work1 as shown more clearly in Figure 14.

In using this invention for sharpening` the stationary or ground blade 111, the latter is secured to the upright 1055 b v means ot a screw 108a that enters the same hole 122 in the ears 128 of the ground plate and which hole serves as the means by which the egroun d plate is secured to the mower, thereby dispensing` with the necessity oi" using clanu'is as has heretofore been done in machines ot' this `general character.

In ground plates orn this character there is a i clearance 124 between the cars 122-5 at the ends of the ground plate and the cutting edge ot the ground plate. hcn the ground plate laxis ofrrotation of thegrinding wheel vwill engage the edge of the ground blade as shown in Figure 8, to sharpen the latter..v In this position it will be manifest that the grinding wheel 417 will engage the ground plate to the Vendof the plate and by reason of thejclearance' 12,4 and the position and shaperof the grinding wheel 4:7, the latter will pass through the clearancevspace 124 without interfering with or being obstructed lin its Amovement by the ears 123. A

' While the preferred forms of the invention have been herein shown and described, `it is to be understood that various changes may be made inthe details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention. Y

That is claimed as new is Y 1. In combination, a base, a lawn mower support mounted for pivotal movement with respect tothe base and on an upright pivot, a sharpening element mounted for bodily vertical movement with respect to said base and said support and also or'pivotal movement toward and away from the lawn mower support on a horizontal axis, and means for effecting such movements of the said element.

2. In combination, a` base, aV lawn mower support mounted for` pivotal movement with respect to the base on an upright pivot, a sharpening element supporting structure mounted for bodily vertical movement with respect to the base and the llrst said support and also for pivotal movement towards and away from the latter on a horizontal pivot, a sharpening element, means for actuating the latter, the-said element and its operating means being mounted upon the second recited support, and Vmeans for` eflecting the said movements of the latter.

3. In combination, a base, aV lawn mower' support mounted for pivotal movement with respect to the base"V and on an upright pivot, av sharpening element mounted for bodily vertical movement with respect to-` said base and said support and also for pivotal movement toward and away from the lawn mower support on a .horizontal axis, means for effecting such movements of the said element, and means for retracting the sharpening element with respect to the lawn mower sup port` t. Incombination, a base,fa lawn mower support-mounted forpivotal movement with respect to the base and on an upright pivot, a sharpening element mounted Vfor bodily vertical movement with respect kto said base and said support and also for pivotal movement toward and away from the lawn mower support on a horizontal axis, means for effecting ,such movements of the saidj element,

means tendingnormally to. movethe said element supporting structure about its pivot in a direction towards the vmower support, and means' for retractingat will thefsharpv eningelement.

5 In combination, a base, a lawn mower support mounted for pivotal ,movement with respect to the base and on an uprightpivot,

a sharpening element mounted for bodily movement with respect to said base and said support and alsofor pivotal movement to- -f ward and away from the lawn mower support on ahoriz'ontal axis, mea-ns for eff-ecting such movements of the said element resilient meanstending normally to move. the said element supporting structure about its pivot in a direction towards the support, and means for varying at will the stress of the said resilient means.

6. In combination, a lawn mower support a sharpening element mounted for bodily vertical movement'with respect toV the first recited support and also for pivotal movement towards and away from the mower support 'on' a horizontal pivot, means for effecting such movements, a rotatable sharp-v ening element, and ajmotor for actuating the element, both supported by the ysecond reci'ed support and bodily -movable ther-ewit v 7. In combination, a lawn mower support, a sharpening element support mounted for vertical movement with respect to the first recited support and also for pivotal 'movement towards andaway from the mowersupport on a horizontal pivot, means for efectingl such movements, -a rotatable sharpening element, aV motor for Vactuating the element, both supported by the second recited support and bodily movable therewith, -and means for retracting the said sharpening element at will and with support. l

8. In combination, a supporting structure, a carriage for receiving and holding a lawn respect to the second recited mower and adapted to traverse said structure, a sharpening element supporting structure mounted forbodily vertical movement Ywith respectto the irst said structure and also for pivotal movement towards and away from the latter on a horizontal pivot, a vsharpening element A and actuating means Y therefor, both mounted upon the second recited structure, and, means for effecting the said movements of the later.

9. lIn combination, a base, a support connected with the basefor movementl on an upright pivot, a lawn mower carriage mounted for free traveling movement back `and forth upon said support, a sharpening element supporting ,structure mounted forl bodily vertical movement with respect to said base and the first said support and also for pivotal movement toward and away from the iirst said support lon a horizontal pivot,v means i iso for eti'ecting such movements of the sharpening element support, a sharpening element, and means tor actuating the latter, both mounted upon and movable with the sharpening element support.

10. In a lawn mowergrind-er, the combination ot a swinging support, a. grinding wheel rotatably supported thereby, a roller .carried by said lsupport adapted to engage with the under surface of the spiral reel knives of a lawn mower, means 'tor rotating said grinding wheel, means mounting said roller tor bodily adjustment whereby it may be moved out of the way so as not to interfere with the positioning of another blade ofthe mower to be sharpened, and means for retracting at will tl id grinding wheel with respect to the said swinging support.

ll. In combination, a` lawn mower snpp 1'ting carriage, guides upon which the 'arriage moves, a. swinging support separate from the carriage, a grinding wheel rotatably supported thereby, means tor rotating the grinding wheel, saidv grinding wheel being ixed while the said carriage is reciprocable upon its guides, and means yieldingly holding the grinding wheel in contact with the work.

l2. In combination, a lawn mower snpporting carriage, guides upon which the cai'- riage moves, swinging support separate from the carriage, a grinding wheel rotatably supported thereby, means i'or rot-ating the grinding wheel, said grinding wheel being iixed wlii'le the said carriage is reciprocable upon its guides, means yieldingly holding the grinding wheel in contact with the work, a roller carried with said swinging support adapted to engage. with the under surface of the spiral reel knives of a lawn mower, and means adapting said roller to be moved out ot' the way with respect to the grinding wheel so as not to interfere with the positioning ot another blade ot the mower to be sharpcned. Y

1 3. I n combination, a lawn .mower` supporting carriage, guides upon which the cai'- riage moves. a swinging support separate trom the carriage, a grinding wheel rotatably supported thereby. means for rotating the grinding wheel, said grinding wheel being lixed while the said carriage is reciprocable upon its guides. and an adjustable rest carried with the carriage and against which a portion of the mower has engagement for positioning the mower upon the carriage and to accommodating different sizes o t mowers.

14.-. In a lawn mower grinder, the combination of a traveling mower supporting carriage.' guides for the carriage, rollers connected with the carriage and engaging the guides, certain or" said rollers and the co-opercing guide being provided one with a groove and the other. extending into the groove to insure a straight travel ot the carringe, a swinging support, a grinding wheel rotatably supported thereby, a roller carried by said support adapted to engage with the under side of the spi 'al knives of a lawn mower, and means tor rotating the grinding wheel.

l5. In a lawn mower grinder, the combination ot a swinging supportv` a hollow grinding wheel rotatably supported thereby, means co-operating with said grinding wheel and adapted to engage with the under surface ot the particular spiral reel kni'te ot' a lawn mower which is being operated upon by the grinding wheel, and means for rotating the grinding wheel.

16, In a lawn mower grinding machine spaced uprights.y one of said upriglits having seats opening through the top-thereof, supporting members engaging over the top edges ot the uprights, a forniation on one ot said elements adapted to enter said openings, bearings carried by Said members, means securing the other of said members against relative movement with respect to its upright, and means tor imparting a turther adjustment to the last said member when secured by the last said means.

17. In a lawn mower grinding machine spaced supports, work holding members engaging over the top of said uprights, means tor securing each of said work holding members tor predetermined adjustments with relation to their respective supports, and means in addition to the last recited means for imparting a turther adjustment to one ot the said work holding members with relation to its support when its respective li'rst said means is active.

18. In a lawn mower grinding machine spaced supports, work holding members engaging over the top oi said upriglits, means for securing each ot said worl' holding members for predetermined adjustments with relation to their respective supports, means in addition to the last recited means for imparting a further adjustment to one ot the said work holding members Awith relation to `its support when its respective first said means is active. the said additional means embodying spaced bearings carried by the work holder, an element intermediate lsaid bearings, screws threaded through said bearings and engaging the ends of said intermediate element, and means adjustably securing said intermediate clement to its respective support.

1S). In a lawn mower grinder, a hollow grindinr wheel mounted tor rotation on a horizontal axis, and means mounting the wheel with its open side adjacent the work and in a position that the edge oi the grinding wheel above the axis ot' the wheel will operate upon the rotary blade ot a lawn mower cutter reel. j

20. In a lawn mower grinder, a hollow grinding Wheel mounted for rotation on a horizontal axis,` ineans mounting the Wheel with its open side adjacent the Work and in a position that the edge of the grinding Wheel above the axis of the Wheel will operate upon the rotary blade of a lawn mower cutter reel, and a supporting element adjacent the open face of the Wheel and engaging the lower edge of the Work.

In testimony whereof I have signed my Y naine to this specification on this 18th day of Ju1y,A. D. 1928. I HENR'YI. HARDINGE. 

